Class 8 Maths Worksheet: Algebraic Identities
The method (Split into easy parts): (a + b)² = a² + 2ab + b². (a − b)² = a² − 2ab + b². (a + b)(a − b) = a² − b²; so a² − b² = (a + b)(a − b). a² + b² = (a + b)² − 2ab = (a − b)² + 2ab.
NameDateTime takenScore ___ / 40
- 1.If a − b = 3 and ab = 108, what is a² + b²?
- 2.Use (a − b)² = a² − 2ab + b² to find 65².
- 3.Use (a − b)² = a² − 2ab + b² to find 21².
- 4.If a + b = 12 and ab = 27, what is a² + b²?
- 5.Use a² − b² = (a + b)(a − b) to find 98² − 87².
- 6.Use (a − b)² = a² − 2ab + b² to find 49².
- 7.Use (a − b)² = a² − 2ab + b² to find 46².
- 8.Use a² − b² = (a + b)(a − b) to find 55² − 13².
- 9.Use (a + b)² = a² + 2ab + b² to find 91².
- 10.If a + b = 3 and ab = 2, what is a² + b²?
- 11.Find the value of x² − 2xy + y² when x = 12 and y = 7.
- 12.If a + b = 10 and ab = 21, what is a² + b²?
- 13.Use a² − b² = (a + b)(a − b) to find 47² − 19².
- 14.Use a² − b² = (a + b)(a − b) to find 37² − 27².
- 15.Find the value of x² + 2xy + y² when x = 11 and y = 1.
- 16.Use (a + b)² = a² + 2ab + b² to find 36².
- 17.Use (a + b)² = a² + 2ab + b² to find 62².
- 18.Use (a + b)(a − b) = a² − b² to find 74 × 66.
- 19.Use a² − b² = (a + b)(a − b) to find 24² − 13².
- 20.Find the value of x² + 2xy + y² when x = 15 and y = 4.
- 21.Use (a + b)(a − b) = a² − b² to find 21 × 19.
- 22.Use (a + b)(a − b) = a² − b² to find 26 × 14.
- 23.Use (a + b)² = a² + 2ab + b² to find 45².
- 24.If a + b = 5 and ab = 6, what is a² + b²?
- 25.Find the value of x² + 2xy + y² when x = 13 and y = 9.
- 26.Use (a + b)(a − b) = a² − b² to find 67 × 53.
- 27.Find the value of x² − 2xy + y² when x = 11 and y = 1.
- 28.Use (a − b)² = a² − 2ab + b² to find 39².
- 29.Find the value of x² − y² when x = 11 and y = 3.
- 30.If a − b = 1 and ab = 42, what is a² + b²?
- 31.Use (a + b)(a − b) = a² − b² to find 75 × 65.
- 32.Find the value of x² − y² when x = 4 and y = 2.
- 33.Use (a + b)² = a² + 2ab + b² to find 107².
- 34.Use (a + b)² = a² + 2ab + b² to find 43².
- 35.Find the value of x² − y² when x = 14 and y = 5.
- 36.Find the value of x² − 2xy + y² when x = 8 and y = 3.
- 37.Use (a + b)² = a² + 2ab + b² to find 74².
- 38.Use (a + b)² = a² + 2ab + b² to find 102².
- 39.Use (a + b)² = a² + 2ab + b² to find 15².
- 40.Find the value of x² + 2xy + y² when x = 14 and y = 2.
Answer key
- 225
- 4225
- 441
- 90
- 2035
- 2401
- 2116
- 2856
- 8281
- 5
- 25
- 58
- 1848
- 640
- 144
- 1296
- 3844
- 4884
- 407
- 361
- 399
- 364
- 2025
- 13
- 484
- 3551
- 100
- 1521
- 112
- 85
- 4875
- 12
- 11449
- 1849
- 171
- 25
- 5476
- 10404
- 225
- 256
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets